The present invention relates generally to absorptive materials, and more particularly to construction of an absorbent composite fiber having an enhanced fluid absorptive and retentive capability as well as relating to use of the absorbent composite fiber for absorbent article constructions such as diapers, pads, surgical dressings and like articles.
The field of absorbent products has seen continual improvement over the years, realizing absorbent materials and products made from those materials with improved containment. Prior technologies have generally used a shared relationship between the thickness of an absorbent article and the absorbent capacity of that article. For example, thickening the material of an article in order to increase its absorbency can result in a concomitant reduction in comfort when the article is worn. Solutions to problems at the interface between absorbency and comfort have included a reduction in the thickness of the material used, but often with an accompanying reduction of absorbency; alternatively, greater absorbency (and retention) is achieved at the cost of thicker, bulkier constructions. Thus, even though tremendous improvements have been made over the years in this field, offering materials with greater absorbency and improved coatings, personal use absorbent article constructions have nonetheless continued to be relatively thick and, therefore, somewhat uncomfortable when used. The addition of bulk to enhance absorbency for some absorbent constructions, such as adult briefs for bladder-bowel control (i.e., adult diapers), can interfere with normal clothing, and can be a cause of embarrassment. Too, although the fluid retentive abilities of such constructions can be quite good, their odor retention capabilities can be lacking, again creating a possible social embarrassmentxe2x80x94particularly for older adults.
Adults, being more sensitive to the social issues associated with odors, appreciate the confidence of being able to go into a workplace, or a social situation, or engage in an athletic activity, without fear of leakage, or odor escapement, and with longer periods of time between changes.
The present invention provides an improvement over the current technology in addressing many of these concerns.
The present invention is first directed to an absorbent fiber having both hydrophilic and hydrophobic qualities. Embodiments of the invention utilize the absorbent fiber for the construction of various articles with enhanced absorptive abilities and retention of both liquid and attendant odors.
Broadly, one aspect of the present invention is directed to an absorbent fiber constructed to absorb and entrain a liquid by capillary action. In addition to absorption and retention of the liquid, the capillary action afforded by the absorbent fiber functions to retain odors that may be associated with the absorbed liquid. In one embodiment of this aspect of the invention the fiber is constructed from a liquid impervious material, such as plastic, rubber, or other like material, forming an elongate, hollow tube. The fiber is dimensioned to permit the operation of capillary action for liquid recovery and retention. In one embodiment of the invention, the absorbent fiber is a composite construction in which the interior of the fiber includes an absorbent, hydrophilic material to enhance absorbency and retention of both liquids and odors. In addition, the material of such a composite absorbent fiber may be of a type that can crystallize or otherwise harden when wet in a manner that permits such material furthest from the fiber""s point of absorption will harden or crystallize first to thereby seal and contain the absorbed liquid. Alternatively, other materials may be included in the interior of the fiber to add a thinning property to the liquid being absorbed to enhance absorption.
In another embodiment of the invention, the composite construction of the absorbent fiber may constructed by using a woven fabric or material to form the tube-like exterior of the fiber for housing one or another of the absorbent materials. The weave can be chosen to adjust the rate of liquid absorption and retention.
The absorbent fiber of the present invention lends itself to being combined with, or to include, various monitoring devices so that, therefore, further embodiments of the invention have included in the interior of the absorbent fiber sensor devices capable of providing an indication of the amount of liquid absorbed, and/or when the article employing the fiber is reaching its absorbent capacity.
Further, the absorbent fiber of the present invention finds particular advantage when used as a liquid communicative bridge or connector between a site of absorption and a reservoir for liquids collected at the absorption site. Accordingly, the absorbent fiber of the present invention may connect to reservoirs formed as pads that can be strapped to or otherwise inconspicuously be carried by the user, or to a colostomy bag. Also, the reservoir may be formed as an article that can be worn, such as an undershirt. Further still, the reservoir can be permanently affixed to the absorptive element, or removably connected so that the reservoir can be removed and replaced with another reservoir when the first has reached its storage capacity.
The absorbent fibers of any of the aspects of the invention may be used alone, or in combination with other fibers, and is particularly adapted to the construction of such articles as disposable diapers, incontinence pads, sanitary napkins, tampons, headbands, absorbent vests, panty liners, underpants, undershirts, sweatshirts, socks, or any other garment or articles requiring absorption and containment of bodily or other fluids. And, when so used, the fibers may be apertured along their lengths to permit the admission of liquids. Absorbent fibers of the present invention so apertured can be included in an article that can advantageously placed only at the source of the liquid or bodily fluid to be absorbed without fear that the absorbed liquid may leak from other portions of the fiber.
There are a number of advantages achieved by the present invention. An article using the absorbent fiber of the present invention can provide an absorbing ability without the bulk or odor of prior devices and articles. The retention of absorbed liquid by capillary action in a liquid impervious tube will ensure that the liquid and its attendant odor cannot escape.
The tubular construction of the either the hollow or composite fiber allow for the implantation of a liquid-responsive material in the tube of the absorbent fiber to initiate action in the presence of the absorbed liquid such as triggering the release of anti-allergens, or anti-bacterial, or the like.
Further, absorption by capillary action permits products to be constructed with greater absorbing capacity than heretofore available. The use of capillary action provides the ability to transport absorbed liquids to locations remote from the source of the liquid being absorbed, greatly extending the life between changes of absorbent products. Thus, such products as tampons, diapers, colostomy bags, and the like, when made from the composite absorbent fiber of the present invention, can be worn or used longer before removed and/or replaced.